Alleviating difficulties found in operating door closers remains an area of interest. Present door closers suffer from a variety of limitations and disadvantages relative to certain applications. Door closers are utilized in many applications where a door must be shut after opening. This allows the user to pass through the doorway without manually closing the door. Door closers may utilize a spring assembly to close the door and a damper to ensure that the door does not slam closed. In order for the spring to properly shut the door, the door closer may be configured such that the spring is compressed upon opening the door and allowed to expand in order to close the door.
Government regulations may require that the door be capable of opening with a limit on the force required for opening. As an example, the United States Americans with Disabilities Act requires a door be capable of opening with a limit of 5 pounds force at 34 inches from the door hinge line. Utilizing a spring that allows a door to open within these limits may not be strong enough to close the door. Such conditions that would prevent the door from closing with a weak spring may include, for example, a pressure differential across the doorway, a heavy door, high friction within the door system, or a combination thereof. In order to stay within the above-described limits, some door closers have incorporated a motor to assist in opening and closing the door that requires a source of external power. While there have been various attempts at improving door closing technology, there is a need for further contributions to this technology.